<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <title>book</title>
    <style type="text/css">
    	
    </style>
    
  </head>
  <body>
  	<!-- <div id="login">123
        用户名：<input type="username" name="username">
        密码：<input type="password" name="password">
            <button class="btn_login">登录</button>
        <button class="btn_cancal">取消</button>
      </div>-->
    <div id="app"></div>
    <!-- built files will be auto injected -->
    <script type="text/javascript">
        /*var login=document.getElementsByClassName("btn_login");
        var a=Array.prototype.slice.call(login,0);
        console.log(Array.isArray(a));
        console.log(a);
        console.log(login);
        a[0].onclick=function(){
          var insertText="<div id="app"></div>";
          document.getElementById("login").innerHTML(insertText);
            
        }*/
    </script>
  </body>
</html>
